Arrangement for guiding and supporting a tabletop for lengthwise movement

ABSTRACT

Two closed-path ball races, incorporated between the tabletop and respective outer guide rails are covered in part by a flat guide rail on the bottom surface of which a tabletop drive mechanism can be mounted.

United States Patent [72] Inventor HansWorm 45 Schaberg, D-565, Solingen, Germany 792,999

[21] Appl. No, [22] Filed 1 Jan. 22, 1969 Patented Jan. 26, 1971 FOREIGN PATENTS 244,914 5/1963 Australia......................

Primary Examiner-Bobby R. Gay

[32] Priority Oct. 30, 1968 [3 3] Switzerland 308/ 6C [3 1 16199/68 Assistant Examiner-Peter A. Aschenbrenner [54] ARRANGEMENT FOR GUIDING AND Attorney-Sughrue, Rothwell, Mion, Z1nn & Macpeak SUPPORTING A TABLETOP FOR LENGTHWISE MOVEMENT 9 Claims, 10 Drawing Figs.

308/6 ABSTRACT: Two closed-path ball races, incorporated Fl6c 31/06 between the tabletop and respective outer guide rails are [50] Field 01 covered in part by a flat guide rail on the bottom surface of which a tabletop drive mechanism can be mounted.

[51] Int. 137, 143; 248/430; 269/289, 309; 308/6, 6C

ARRANGEMENT FOR GUIDING AND SUPPORTING A TABLETOP FOR LENGTIIWISE MOVEMENT BACKGROUND OF TH E INVENTION The invention relates to a guide arrangement for guiding and supporting a tabletop (that is, the upper, flat member of a table) for lengthwise movement, the arrangement including two outer guide rails between which the tabletop moves, movable bearings, two closed-path races for the bearings, each race comprising a rolling path, a return path, and two connecting paths, whereby each race forms a closed path about which the bearings are free to move, holding means for preventing the bearings from falling out of at least the rolling path, a race in each outer guide rail for the rolling path, two spaced edges incorporated by the holding means, and a groove in each outer guide rail race for accepting a respective holding means edge.

Guide arrangements of this kind are known, and are conventionally constructed using steel sectors that incorporate ball bearing races, the sectors being screwed or bolted to the tabletop. The sectors project downwards out of the tabletop. In most cases, the tabletop must be fitted with a drive, such as a mechanical mechanism having a spindle and a nut or a hydraulic arrangement with a piston, piston rod, and a cylinder. Where the guideways are narrow, to save space, the sectors are set so close to one another that there is often no room to mount the drive parts on the tabletop.

Where the loading is considerable orthe table is relatively long, several pairs of sectors are customarily arranged one behind the other. In this case, it is often difiicult to obtain a uniformly distributed loading and guiding.

SUMMARY OF THE INVENTION The purpose of the invention is to produce a guide arrangement having two bearing races, the arrangement being easily adjustable to eliminate play and leaving sufficient space to mount drive parts, such as a nut for a spindle, a cylinder, or a piston rod.

In a particularly advantageous embodiment of the invention, the guide rail is made in two parts and adjusted in position with respect to the outer rails by spacers or resilient elements.

BRIEF DESCRIPTION OF THE-DRAWINGS The invention will be described, with reference to the figures of the drawings, wherein:

FIG. 1 is a view, taken along line H of FIG. 2, of one form of the guide arrangement;

FIG. 2 is a view of the underside of a tabletop provided with the guide arrangement of the invention, several of the parts being either partly cut away or removed;

FIG. 3 is a front view of one form of the guide rail;

FIG. 4 is a front view of another form of the guide rail;

FIG. 5 is a perspective view of a cover for a connecting path of a race;

FIG. 6 is a top view of the guiding and holding plate for the bearings;

FIG. 7 is a perspective view of the two race paths;

FIG. 8 is a perspective view of a tabletop with races that form an integral part of the top;

FIG. 9 is a perspective view of the tabletop shown in FIG. 8, the guide rail shown in FIG. 3, and the plate shown in FIG. 6, all parts being assembled and the races filled with ball bearings; and

FIG. 10 is a perspective view of the complete guide arrange ment 'as seen from below, the two-part guide rail shown in FIG. 4 being used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The guide arrangement of the invention is located between a tabletop l, which has a perfectly flat upper surface, and two outer guide rails 2, between which latter the tabletop is movable lengthwise. Ball bearings 3 are held in races between the tabletop l and each rail 2. Each of the two races is composed of a rolling path 4, two connecting paths 5, and a return path 6. Only the ball bearings in the rolling path 4 guide and support the tabletop in the guide rails 2. The race for the rolling path 4 is actually composed of two races, the one race 2a being embodied in each guide rail 2 and the other race 7a being embodied in a flat guide rail 7, which is bolted to the tabletop l. The race paths 5 and 6 are made integral with the bottom surface of the tabletop, as shown in FIG. 8. A metal plate 8, shown in FIG. 6, is bolted to the underside of the tabletop to prevent the ball bearings 3 from falling out of the races and to guide them in their movement. The outer edge 8a of the plate 8 extends with clearance into a groove 9 of each rail 2. The curved edges 8b are considerably stressed and, therefore, advantageously hardened.

Metal covers 10 of which one is illustrated in FIG. 5 cover the connecting paths 5.

As shown in FIG. I, the underside of the rail 7 has a flat surface for the easy mounting of parts for driving the tabletop. Two such parts, a nut 11 and a drivespindle 12, are shown in dot-dash line mounted on the rail 7. Instead of these parts, a hydraulic drive can be fitted.

A playless adjustment of the tabletop 1 can be obtained, for example, by moving one of the guide rails 2 towards the other, using adjusting screws, not shown.

Another way of obtaining this playless adjustment is to use a two-piece guide rail 13 (see FIGS. 4 and l0)in place of the one-piece rail 7. Each guide-rail part embodies a slanting edge surface 13b opposite the bearing race 13a. Several spacers 14, placed between these surfaces 13b, can be vertically positioned by screws 15 to press the guide rail pieces with the desired force against the rails 2 through the bearings 3. Resilient elements, such as springs, can be substituted for the spacers 14.

When the guide rail 7 or 13 is relatively long, the races 7a or 13a are advantageously ground out somewhat, or otherwise enlarged, along the middle portion of the rail. In this way, only those ball bearings located at the beginning and end of the races 7a or 13a are used as load-bearing and guide elements, whereby the tabletop moves more easily and smoothly.

The bearing race paths 5 and 6 formed as an integral part of the tabletop enable a reduction in the cost of machining the bearing races. The tabletop can be a metal casting, in which case the paths 5 and 6 are cast integrally with the top, or made of a suitable synthetic plastic, the paths 5 and 6 being molded into the tabletop.

Although the preferred embodiments of the invention have been described, the scope of, and the breadth of protection afforded to the invention are limited solely by the appended claims.

I claim:

I. An arrangement for guiding and supporting a tabletop for lengthwise movement, including two outer guide rails between which the tabletop moves, bearings, two races for said bearings, each said race comprising a rolling path, a return path, and two connecting paths, each said connecting path connecting one end of said rolling path to the corresponding end of said return path, whereby each said race forms a closed path about which said bearings are free to move, holding means (8) for preventing said bearings from falling out of at least said rolling path, two spaced edges incorporated by said holding means, a race (20) in each said outer guide rail for said rolling path, and a groove (9)'in each said outer guide rail race for accepting a respective said holding means edge, and wherein in the improvement comprises that said connecting and return paths are arranged in the tabletop, a flat guide means (7 or 13) and a cover (10) for covering said connecting and return paths so that the upper surface of the tabletop and the lower surface of said flat guide means are flat and smooth for the mounting of a drive mechanism for the table.

2. The arrangement as defined in claim 1, wherein said flat guide means (13) is located between said two outer guide rails and comprises two spaced parts, and means for pressing each said part against the respective said outer guide rail through said bearings to eliminate play.

3. The arrangement as defined in claim 2, wherein said pressing means comprises at least one adjustable spacer (14!) positioned between said two parts and acting thereon.

4. The arrangement as defined in claim 2, wherein said pressing means comprises at least one resilient element positioned between said two parts and acting thereon.

5. The arrangement as defined in claim ll, including a bearing race in said guide means for each said rolling path cooperating with a respective said guide rail race. a

6. The arrangement as defined in claim 5, wherein each said guide means race is enlarged along the central part of its length so that only those bearings at the beginning and end of said rolling path act as load-bearing and guide elements.

7. The arrangement as defined in claim I, wherein said holding means is metal and incorporates a respective hardened edge for cooperating with each said connecting path.

8. The arrangement as defined in claim I, wherein the tabletop is made of synthetic plastic and said connecting and return paths are molded into the undersurface of the tabletop.

9 The arrangement as defined in claim 1, wherein each said closed race extends in the lengthwise direction of the tabletop, said connecting and return paths are integrally incorporated in the underside of the tabletop, said flat guide means is located between said two outer guide rails and on the under side of the tabletop, and including a race (7a or 13a) in said flat guide means for each said rolling path, each said latter race being positioned opposite a respective said outer guide rail race to form therewith a complete said rolling path, whereby only those bearings in said rolling path serve to support and guide the tabletop in said outer guide rails. 

1. An arrangement for guiding and supporting a tabletop for lengthwise movement, including two outer guide rails between which the tabletop moves, bearings, two races for said bearings, each said race comprising a rolling path, a return path, and two connecting paths, each said connecting path connecting one end of said rolling path to the corresponding end of said return path, whereby each said race forms a closed path about which said bearings are free to move, holding means (8) for preventing said bearings from falling out of at least said rolling path, two spaced edges incorporated by said holding means, a race (2a) in each said outer guide rail for said rolling path, and a groove (9) in each said outer guide rail race for accepting a respective said Holding means edge, and wherein in the improvement comprises that said connecting and return paths are arranged in the tabletop, a flat guide means (7 or 13) and a cover (10) for covering said connecting and return paths so that the upper surface of the tabletop and the lower surface of said flat guide means are flat and smooth for the mounting of a drive mechanism for the table.
 2. The arrangement as defined in claim 1, wherein said flat guide means (13) is located between said two outer guide rails and comprises two spaced parts, and means for pressing each said part against the respective said outer guide rail through said bearings to eliminate play.
 3. The arrangement as defined in claim 2, wherein said pressing means comprises at least one adjustable spacer (14) positioned between said two parts and acting thereon.
 4. The arrangement as defined in claim 2, wherein said pressing means comprises at least one resilient element positioned between said two parts and acting thereon.
 5. The arrangement as defined in claim 1, including a bearing race in said guide means for each said rolling path cooperating with a respective said guide rail race.
 6. The arrangement as defined in claim 5, wherein each said guide means race is enlarged along the central part of its length so that only those bearings at the beginning and end of said rolling path act as load-bearing and guide elements.
 7. The arrangement as defined in claim 1, wherein said holding means is metal and incorporates a respective hardened edge for cooperating with each said connecting path.
 8. The arrangement as defined in claim 1, wherein the tabletop is made of synthetic plastic and said connecting and return paths are molded into the undersurface of the tabletop. 9 The arrangement as defined in claim 1, wherein each said closed race extends in the lengthwise direction of the tabletop, said connecting and return paths are integrally incorporated in the underside of the tabletop, said flat guide means is located between said two outer guide rails and on the under side of the tabletop, and including a race (7a or 13a) in said flat guide means for each said rolling path, each said latter race being positioned opposite a respective said outer guide rail race to form therewith a complete said rolling path, whereby only those bearings in said rolling path serve to support and guide the tabletop in said outer guide rails. 